Created the ChatController

src/server/CookingApp/Common/CompletionConstants/Completions.cs

@@ -2,7 +2,7 @@
 {
     public class Completions
     {
-        public const string Instructions = "You are a helpful assistant that answers questions related to cooking tips, recipes, kitchen tips. \" +" +
+        public const string AssistantInstructions = "You are a helpful assistant that answers questions related to cooking tips, recipes, kitchen tips. \" +" +
             "\r\nYou will receive queries containing different questions on cooking thematic or a list of products that you have to make use of and come up with a recipe for the user.\" +" +
             "\r\nYou need to take into account the user's dietary needs and their allergies so that you do not suggest a recipe that includes unhealthy or inappropriate contents. \" +" +
             "\r\nHere is a list of the user's allergies:";
@@ -54,5 +54,7 @@ public class Completions
                     "\r\nAdjust the seasoning according to your taste preference." +
                     "\r\nFeel free to add other herbs or spices that you like." +
                     "\r\nEnjoy your meal!";
+
+        public const string TitleGenerationPrompt = "Generate a title from this sentence:";
     }
 }

src/server/CookingApp/Common/ExceptionMessages.cs

@@ -4,6 +4,11 @@ public static class ExceptionMessages
     {
         public const string NullOrEmptyInputValues = "The provided input contains either null or an empty value";
         public const string SubscriptionCreationFail = "Failed to create a subscription. {0}";
-        public const string ResponseRequestFailed = "The ChatGPT API failed to respond. Please try again.";
+
+        public class ChatGPT
+        {
+            public const string ResponseError = "The ChatGPT Service failed to respond. Please try again.";
+            public const string ConnectionError = "Something went wrong. Follow the log for more information.";
+        }
     }
 }

src/server/CookingApp/Common/SuccessMessages.cs

@@ -0,0 +1,10 @@
+namespace CookingApp.Common
+{
+    public class SuccessMessages
+    {
+        public class ChatGPT
+        {
+            public const string ResponseSuccess = "Response received successully.";
+        }
+    }
+}

src/server/CookingApp/Common/TaskInformationMessages.cs

@@ -0,0 +1,10 @@
+namespace CookingApp.Common
+{
+    public class TaskInformationMessages
+    {
+        public class ChatGPT
+        {
+            public const string ConnectionAttempt = "Attempting to establish connection with ChatGPT API.";
+        }
+    }
+}

src/server/CookingApp/Controllers/ChatController.cs

@@ -0,0 +1,72 @@
+namespace CookingApp.Controllers
+{
+    using CookingApp.Common;
+    using CookingApp.Models.DTOs;
+    using CookingApp.Services.ChatHistory;
+    using Microsoft.AspNetCore.Authorization;
+    using Microsoft.AspNetCore.Mvc;
+
+    [ApiController]
+    public class ChatController : ControllerBase
+    {
+        private readonly IChatService _chatService;
+        private readonly ILogger<ChatController> _logger;
+
+        public ChatController(IChatService chatService, ILogger<ChatController> logger)
+        {
+            _chatService = chatService;
+            _logger = logger;
+        }
+
+        [HttpGet("chats")]
+        public async Task<IActionResult> GetChats()
+        {
+            //TODO: implement Azure Entra Id functions
+            //var user = _userService.GetUser();
+            var chats = await _chatService.GetAllByUserId("user.Id");
+            return Ok(chats);
+        }
+
+        [HttpPost("chat-request")]
+        public async Task<IActionResult> SendQuery([FromBody] string message, [FromHeader] string? chatId = null)
+        {
+            try
+            {
+                if (!ModelState.IsValid)
+                {
+                    return BadRequest();
+                }
+
+                _logger.LogInformation(TaskInformationMessages.ChatGPT.ConnectionAttempt);
+
+                var result =
+                    String.IsNullOrEmpty(chatId)
+                    ? await _chatService.CreateChat(message)
+                    : await _chatService.UpdateChat(message, chatId);
+
+                if (result == null)
+                {
+                    _logger.LogError(ExceptionMessages.ChatGPT.ConnectionError);
+                    _logger.LogError(ExceptionMessages.ChatGPT.ResponseError);
+
+                    return NoContent();
+                }
+
+                _logger.LogInformation(SuccessMessages.ChatGPT.ResponseSuccess);
+                // To display the message you need to get into result.Choices[0].Message.Content.
+                // The chat id is also contained inside the result
+
+                return Ok(result);
+            }
+            catch (Exception e)
+            {
+                _logger.LogError(ExceptionMessages.ChatGPT.ConnectionError);
+                _logger.LogError($"{e.Message}");
+
+                return BadRequest();
+            }
+
+            return Ok();
+        }
+    }
+}

src/server/CookingApp/Infrastructure/Extensions/ServiceCollectionExtensions.cs

@@ -15,10 +15,10 @@
 using CookingApp.Services.Stripe;
 using Stripe;
 using CookingApp.Infrastructure.Configurations.Stripe;
-using CookingApp.Services.OpenAI.Completions;
 using OpenAI.Extensions;
 using OpenAI;
 using Microsoft.AspNetCore.DataProtection.KeyManagement;
+using CookingApp.Services.ChatHistory;
 
 namespace CookingApp.Infrastructure.Extensions
 {
@@ -148,7 +148,7 @@ public static IHostApplicationBuilder AddOpenAIIntegration(this WebApplicationBu
                 options.DefaultModelId = builder.Configuration.GetValue<string>("OpenAPIOptions:Model") ?? string.Empty;
             });
 
-            builder.Services.AddScoped<ICompletionService, CompletionService>();
+            builder.Services.AddScoped<IChatService, ChatService>();
 
             return builder;
         }

src/server/CookingApp/Models/DTOs/CreateChatDTO.cs

@@ -0,0 +1,18 @@
+namespace CookingApp.Models.DTOs
+{
+    using MongoDB.Bson.Serialization.Attributes;
+
+    public class CreateChatDTO
+    {
+        public string Id { get; set; }
+        public string? Title { get; set; }
+
+        public string? UserId { get; set; }
+
+        public DateTime CreatedTime { get; set; }
+
+        public List<Request> Requests { get; set; } = new List<Request>();
+
+        public List<Response> Responses { get; set; } = new List<Response>();
+    }
+}